Warming seas may cause more disease, Cornell researchers say.

It’s June 2013: A group of park rangers are walking down a peaceful strip of shoreline in Washington State’s famous Olympic National Park when they spot an alarming sight: dozens of shriveled, gooey-looking purple and orange sea stars trying to cling to a rock.

There’s something wrong, but the rangers are not quite sure what. And little do they know the problem is about to get much, much worse.

Since those first sick sea stars were found in Washington, millions more have been wasting to death all along the West Coast of the U.S., from Alaska to Baja California. A sea star disease epidemic of unknown magnitude decimated up to 90 percent of sea star populations in some parts of the Pacific Northwest between 2013-2014, and, while the epidemic has since slowed, sea stars are still dying.